12,875 research outputs found

    Logarithmic temperature dependence of Hall transport in granular metals

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    We have measured the Hall coefficient RHR_H and the electrical conductivity σ\sigma of a series of ultrathin indium tin oxide films between 2 and 300 K. A robust RHR_H\,\propto\,lnTT law is observed in a considerably wide temperature range of 2 and \sim120 K. This lnTT dependence is explained as originated from the electron-electron interaction effect in the presence of granularity, as newly theoretically predicted. Furthermore, we observed a σ\sigma\,\propto\,lnTT law from 3 K up to several tens K, which also arose from the Coulomb interaction effect in inhomogeneous systems. These results provide strong experimental supports for the current theoretical concepts for charge transport in granular metals with intergrain tunneling conductivity gTg_T\gg1.Comment: 4 pages, 5 figures, Phys. Rev. B (accepted

    A Numerical Solution of Wave Equation for Dynamic Compaction of Soil

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    It is a known fact that any disturbance at the ground surface, like the one created by vibratory, compactors or by application of blast pressure on detonation of a foamed propellant, is transmitted into ground until it is weak enough to travel deeper and farther. The ground acceleration at various points, induces compaction. The transmission of vibrations due to such surface dynamic loads are governed by the equation of motion based on Newton\u27s second law. The equation of motion is presented in Euiler\u27s Coordinates using tensor notation and is solved for surface displacements due to surface dynamic loads. These loads are likely to be experienced over a half space due to movement of vehicles, compactors etc. The paper presents a finite difference iterative method for solving the above equation which permits the simultaneous solution of two partial differential equations in plane strain condition. Results of the present analysis have been compared with those available from theory of elasticity

    Finding Pairwise Intersections Inside a Query Range

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    We study the following problem: preprocess a set O of objects into a data structure that allows us to efficiently report all pairs of objects from O that intersect inside an axis-aligned query range Q. We present data structures of size O(n(polylogn))O(n({\rm polylog} n)) and with query time O((k+1)(polylogn))O((k+1)({\rm polylog} n)) time, where k is the number of reported pairs, for two classes of objects in the plane: axis-aligned rectangles and objects with small union complexity. For the 3-dimensional case where the objects and the query range are axis-aligned boxes in R^3, we present a data structures of size O(nn(polylogn))O(n\sqrt{n}({\rm polylog} n)) and query time O((n+k)(polylogn))O((\sqrt{n}+k)({\rm polylog} n)). When the objects and query are fat, we obtain O((k+1)(polylogn))O((k+1)({\rm polylog} n)) query time using O(n(polylogn))O(n({\rm polylog} n)) storage

    Design of a mm-wave 1:3 Waveguide Power Divider using E-plane Bifurcated Waveguide

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    Analysis of MAGSAT data of the Indian region

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    Progress in the development of software for reading MAGSAT data tapes and for the reduction of anomaly data, and in the preparation of data for magnetic anomaly maps is reported

    Diffuse Sky Radiation in a Dry Turbid Atmosphere

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    Development of a simple method for the assessment of atmospheric turbidity all over the country in all seasons has been attempted. We have been able to derive a reasonably reliable equation relating diffuse sky radiation Dr on a horizontal surface to air mass mr and Angstrom Schuepp turbidity coefficient B, in a dry atmosphere with constant albedo (A = 0.25) of the terrain

    HIV-associated multi-centric Castleman’s disease with multiple organ failure: cuccessful treatment with rituximab

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    Introduction: Multicentric Castleman's Disease (MCD), a lymphoproliferative disorder associated with Human Herpes Virus-8 (HHV-8) infection, is increasing in incidence amongst HIV patients. This condition is associated with lymphadenopathy, polyclonal gammopathy, hepato-splenomegaly and systemic symptoms. A number of small studies have demonstrated the efficacy of the anti-CD20 monoclonal antibody, rituximab, in treating this condition. Case presentation: We report the case of a 46 year old Zambian woman who presented with pyrexia, diarrhoea and vomiting, confusion, lymphadenopathy, and renal failure. She rapidly developed multiple organ failure following the initiation of treatment of MCD with rituximab. Following admission to intensive care (ICU), she received prompt multi-organ support. After 21 days on the ICU she returned to the haematology medical ward, and was discharged in remission from her disease after 149 days in hospital. Conclusion: Rituximab, the efficacy of which has thus far been examined predominantly in patients outside the ICU, in conjunction with extensive organ support was effective treatment for MCD with associated multiple organ failure. There is, to our knowledge, only one other published report of its successful use in an ICU setting, where it was combined with cyclophosphamide, adriamycin and prednisolone. Reports such as ours support the notion that critically unwell patients with HIV and haematological disease can benefit from intensive care

    Modelling the Hydration kinetics of kidney beans (Phaseolus vulgaris) in sodium salts using Response surface methodology

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    The present work investigated the effect of salt solutions of sodium chloride, and sodium bicarbonate on the water uptake by kidney beans (Phaseolus vulgaris) at different temperatures (30, 45 and 60 0C). Thirty-five soaking solutions were prepared using NaCl and NaHCO3 to find the optimum soaking treatment and time to maximise the hydration. Hydration kinetics of kidney beans was studied in different concentrations of the salt solutions and at different temperatures by the method of weight gain until equilibrium conditions were attained. Response surface methodology was used to design the experiments and to optimize the levels for minimum soaking time and to maximize the hydration. The soaking solutions affected the mass transfer in both seed coat and cotyledon, demonstrating changes on both proteins and polysaccharides.  Increasing the temperature from 30 to 60 0 C in sodium chloride solution and sodium bicarbonate solution (0.5, 1.0 and 1.5% concentration) decreased the soaking time from >225min and 225 min to 82.5 min and 73.5 min respectively to achieve around 80% hydration. Beans soaked in sodium bicarbonate solution exhibited higher hydration rates than in distilled water followed by sodium chloride solution at the same salt concentration. Soaking for about three hours at 300C resulted in maximum hydration.  The optimum soaking treatment was found to be in a salt solution containing 1.10% NaCl and 0.92% NaHCO3 at 300C which resulted in a soaking time of 193.45 min.  This work demonstrated a simple and non-tedious approach for enhancing the hydration process of grains. &nbsp

    Mass-Gaps and Spin Chains for (Super) Membranes

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    We present a method for computing the non-perturbative mass-gap in the theory of Bosonic membranes in flat background spacetimes with or without background fluxes. The computation of mass-gaps is carried out using a matrix regularization of the membrane Hamiltonians. The mass gap is shown to be naturally organized as an expansion in a 'hidden' parameter, which turns out to be 1d\frac{1}{d}: d being the related to the dimensionality of the background space. We then proceed to develop a large NN perturbation theory for the membrane/matrix-model Hamiltonians around the quantum/mass corrected effective potential. The same parameter that controls the perturbation theory for the mass gap is also shown to control the Hamiltonian perturbation theory around the effective potential. The large NN perturbation theory is then translated into the language of quantum spin chains and the one loop spectra of various Bosonic matrix models are computed by applying the Bethe ansatz to the one-loop effective Hamiltonians for membranes in flat space times. Apart from membranes in flat spacetimes, the recently proposed matrix models (hep-th/0607005) for non-critical membranes in plane wave type spacetimes are also analyzed within the paradigm of quantum spin chains and the Bosonic sectors of all the models proposed in (hep-th/0607005) are diagonalized at the one-loop level.Comment: 36 Page

    Optimizing Robustness and Invisibility in Digital Image Watermarking: A SVM-Based Multi-Level DWT and SVD Approach

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    This research introduces a new digital image watermarking approach that utilizes discrete wave transformation (DWT), Support vector machine, and singular value decomposition. The method improves robustness under various assault situations by using the SVM classifier during watermark extraction. Multi-level DWT splits the host picture into sub-bands when embedding, and the coefficients are used as input for SVM. After SVD, the scaling factor embeds the watermark. Comparing the proposed approach to existing research under various attacks, the experimental findings demonstrate that it strikes an equilibrium between robustness and invisibility for watermarks of varying sizes. Support Vector Machine is a contemporary category of machine learning techniques that is extensively employed for the purpose of solving classification problems
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